import datetime
from django.db import models
from django.utils import timezone
from django.contrib import admin

class Question(models.Model):
    question_text = models.CharField('问题文本',max_length=200)
    pub_date = models.DateTimeField('发布日期')

    class Meta:
        verbose_name = ('问题')  # 单数形式
        verbose_name_plural = ('问题列表')  # 复数形式

    def __str__(self):
        return self.question_text
    
    @admin.display(
        boolean=True,
        ordering="pub_date",
        description="Published recently?",
    )
    def was_published_recently(self):
        now = timezone.now()
        return now - datetime.timedelta(days=1) <= self.pub_date <= now


    def total_votes(self):
        return self.choice_set.all().aggregate(models.Sum('votes'))['votes__sum'] or 0

class Choice(models.Model):
    question = models.ForeignKey(Question, on_delete=models.CASCADE,verbose_name='问题')
    choice_text = models.CharField('选项文本',max_length=200)
    votes = models.IntegerField('票数',default=0)

    class Meta:
        verbose_name = ('选项')
        verbose_name_plural = ('选项列表')

    def __str__(self):
        return self.question.question_text+'=>'+self.choice_text

